This invention relates to a means for inserting and extracting object, such as miniature lamp bulbs, from relatively inaccessible areas, such as recessed lamp sockets in pushbuttons, keys, indicators or the like.
It will be appreciated that in recent years, there has been increasing tendency to miniaturize electrical devices requiring miniature lamps. As the lamps have become smaller, it also has been convenient to place the lamp socket assembly in relatively inaccessible recessed areas. Obviously, this often presents difficulty in removal and insertion of the recessed lamp or similar object. Initial attempts to solve this problem led to the use of so-called "spaghetti" insulation tubes, which are normally used to contain and protect electrical conductors. The inner diameter of the tubing was of a size that would permit frictional gripping of the elongated lamp bulb. It will be apparent that, although this was a satisfactory means for removing a lamp bulb, it was virtually impossible to use the same means for inserting the lamp bulb, because the tubing would be difficult to remove from the lamp after it was inserted. Later efforts to correct this problem involved the provision of a flexible tubing which was also stretchable to accommodate various size lamps for the removal of the lamp. At the opposite end of the tubing there was provided a relatively small "suction cup" portion which would be attached to the outermost end of the lamp bulb and would temporarily hold the lamp for insertion purposes. In order to remove the suction cup, the tool would have to be canted to the side to break the suction. It will become apparent that if the socket for the lamp bulb was recessed to any degree within a relatively deep, narrow chamber, there would be insufficient spacing to permit sidewise movement for removal of the tool after insertion of the lamp.
Several lamp or similar object extracting and injecting tools have been the subject of U.S. patents. See, for instance, the patents granted to Masland -- U.S. Pat. No. 2,251,148; Oliveri -- U.S. Pat. No. 2,607,620; Wagstaff -- U.S. Pat. No. 2,924,481; Adams -- U.S. Pat. No. 3,284,123 and Peck -- U.S. Pat. No. 3,473,423. Of these listed patents, tools specifically intended for extraction and insertion of lamps, or like objects, in recessed places are those shown in the Oliveri, Wagstaff and Peck patents. In addition, reference is also made of the IBM Technical Disclosure Bulletin, Volume 6, Number 10, Mar. 10, 1964, page 9, wherein G. H. Mack also disclosed a bulb changing tool used for purposes similar to those of the present invention. The tools of Wagstaff, Oliveri and Mack (IBM) each have means for disengaging the tool from the object gripped after insertion of the object. The means in each of these cases is in the form of an axially movable plunger contained within a hollow chamber of an elongated housing member. Pressure applied against the plunger after insertion of the object in its receptacle permitted contact with the object by the plunger to release the frictional or pneumatic grip of the lamp by the tool. It will be apparent that these tools have several cooperating parts requiring additional forming and assembly operations to fabricate a finished tool.
The Adams patent is illustrative of a somewhat similar tool, wherein the "plunger" is an intricately molded member centrally located within the hollow bore of a resiliently formed tool. The Masland patent merely discloses a means for applying a frictional grip for removing "frozen" lamp bulbs from a head-light fixture of an automobile, whereas the Peck patent is quite similar to the Masland construction, but additionally includes a wire brush for cleaning the socket before inserting the tool.
Further illustrations of lamp removing devices may be found in the U.S. Pat. No. 2,545,043 granted to Odenthal and U.S. Pat. No. 2,681,822 granted to Daniels.